diff --git a/src/fsm.c b/src/fsm.c
index 9bbf870..0fdc564 100644
--- a/src/fsm.c
+++ b/src/fsm.c
@@ -213,8 +213,9 @@
 {
 	if (id) {
 		if (!osmo_identifier_valid(id)) {
-			LOGP(DLGLOBAL, LOGL_ERROR, "Attempting to allocate FSM instance of type '%s'"
-			     " with illegal identifier '%s'\n", fi->fsm->name, id);
+			LOGP(DLGLOBAL, LOGL_ERROR,
+			     "Attempting to set illegal id for FSM instance of type '%s': %s\n",
+			     fi->fsm->name, osmo_quote_str(id, -1));
 			return -EINVAL;
 		}
 		osmo_talloc_replace_string(fi, (char **)&fi->id, id);
diff --git a/tests/fsm/fsm_test.err b/tests/fsm/fsm_test.err
index c4ee46f..3e01d48 100644
--- a/tests/fsm/fsm_test.err
+++ b/tests/fsm/fsm_test.err
@@ -38,12 +38,12 @@
   osmo_fsm_inst_find_by_name("Test_FSM(arbitrary_id)") == fi
   osmo_fsm_inst_find_by_id("arbitrary_id") == fi
 osmo_fsm_inst_update_id("")
-Attempting to allocate FSM instance of type 'Test_FSM' with illegal identifier ''
+Attempting to set illegal id for FSM instance of type 'Test_FSM': ""
 [0;m    rc == -22, ok
   osmo_fsm_inst_name() == "Test_FSM(arbitrary_id)"
   osmo_fsm_inst_find_by_name("Test_FSM(arbitrary_id)") == fi
 osmo_fsm_inst_update_id("invalid.id")
-Attempting to allocate FSM instance of type 'Test_FSM' with illegal identifier 'invalid.id'
+Attempting to set illegal id for FSM instance of type 'Test_FSM': "invalid.id"
 [0;m    rc == -22, ok
   osmo_fsm_inst_name() == "Test_FSM(arbitrary_id)"
   osmo_fsm_inst_find_by_name("Test_FSM(arbitrary_id)") == fi